Switching threads at QML breakpoint does not work

1. Create a new Qt Quick Application project with component set "Qt Quick 1.1". Configure it with Qt 4.8.
2. Set a breakpoint in the project's QML file.
3. Run the project in the debugger and hit the breakpoint.
   Above the Stack view you see a combo box showing the current thread, probably #0.
4. Use the combo box for switching to thread #1.
   Nothing happens.

Erik told me that threads can't be switched in this situation so having this combo box is misleading. It should be cleared, disabled or hidden completely.